Commit Graph

69 Commits

Author SHA1 Message Date
Chandler Carruth 2846e9ef15 [PM] Widen the interface for invalidate on an analysis result now that
it is completely optional, and sink the logic for handling the preserved
analysis set into it.

This allows us to implement the delegation logic desired in the proxy
module analysis for the function analysis manager where if the proxy
itself is preserved we assume the set of functions hasn't changed and we
do a fine grained invalidation by walking the functions in the module
and running the invalidate for them all at the manager level and letting
it try to invalidate any passes.

This in turn makes it blindingly obvious why we should hoist the
invalidate trait and have two collections of results. That allows
handling invalidation for almost all analyses without indirect calls and
it allows short circuiting when the preserved set is all.

llvm-svn: 195338
2013-11-21 10:53:05 +00:00
Chandler Carruth 851a2aa0e0 [PM] Add a module analysis pass proxy for the function analysis manager.
This proxy will fill the role of proxying invalidation events down IR
unit layers so that when a module changes we correctly invalidate
function analyses. Currently this is a very coarse solution -- any
change blows away the entire thing -- but the next step is to make
invalidation handling more nuanced so that we can propagate specific
amounts of invalidation from one layer to the next.

The test is extended to place a module pass between two function pass
managers each of which have preserved function analyses which get
correctly invalidated by the module pass that might have changed what
functions are even in the module.

llvm-svn: 195304
2013-11-21 02:11:31 +00:00
Chandler Carruth c0bfa8c231 [PM] Add the preservation system to the new pass manager.
This adds a new set-like type which represents a set of preserved
analysis passes. The set is managed via the opaque PassT::ID() void*s.
The expected convenience templates for interacting with specific passes
are provided. It also supports a symbolic "all" state which is
represented by an invalid pointer in the set. This state is nicely
saturating as it comes up often. Finally, it supports intersection which
is used when finding the set of preserved passes after N different
transforms.

The pass API is then changed to return the preserved set rather than
a bool. This is much more self-documenting than the previous system.
Returning "none" is a conservatively correct solution just like
returning "true" from todays passes and not marking any passes as
preserved. Passes can also be dynamically preserved or not throughout
the run of the pass, and whatever gets returned is the binding state.
Finally, preserving "all" the passes is allowed for no-op transforms
that simply can't harm such things.

Finally, the analysis managers are changed to instead of blindly
invalidating all of the analyses, invalidate those which were not
preserved. This should rig up all of the basic preservation
functionality. This also correctly combines the preservation moving up
from one IR-layer to the another and the preservation aggregation across
N pass runs. Still to go is incrementally correct invalidation and
preservation across IR layers incrementally during N pass runs. That
will wait until we have a device for even exposing analyses across IR
layers.

While the core of this change is obvious, I'm not happy with the current
testing, so will improve it to cover at least some of the invalidation
that I can test easily in a subsequent commit.

llvm-svn: 195241
2013-11-20 11:31:50 +00:00
Chandler Carruth d895e29e88 [PM] Make the function pass manager more regular.
The FunctionPassManager is now itself a function pass. When run over
a function, it runs all N of its passes over that function. This is the
1:N mapping in the pass dimension only. This allows it to be used in
either a ModulePassManager or potentially some other manager that
works on IR units which are supersets of Functions.

This commit also adds the obvious adaptor to map from a module pass to
a function pass, running the function pass across every function in the
module.

The test has been updated to use this new pattern.

llvm-svn: 195192
2013-11-20 04:39:16 +00:00
Chandler Carruth ed1ffe0197 [PM] Split the analysis manager into a function-specific interface and
a module-specific interface. This is the first of many steps necessary
to generalize the infrastructure such that we can support both
a Module-to-Function and Module-to-SCC-to-Function pass manager
nestings.

After a *lot* of attempts that never worked and didn't even make it to
a committable state, it became clear that I had gotten the layering
design of analyses flat out wrong. Four days later, I think I have most
of the plan for how to correct this, and I'm starting to reshape the
code into it. This is just a baby step I'm afraid, but starts separating
the fundamentally distinct concepts of function analysis passes and
module analysis passes so that in subsequent steps we can effectively
layer them, and have a consistent design for the eventual SCC layer.

As part of this, I've started some interface changes to make passes more
regular. The module pass accepts the module in the run method, and some
of the constructor parameters are gone. I'm still working out exactly
where constructor parameters vs. method parameters will be used, so
I expect this to fluctuate a bit.

This actually makes the invalidation less "correct" at this phase,
because now function passes don't invalidate module analysis passes, but
that was actually somewhat of a misfeature. It will return in a better
factored form which can scale to other units of IR. The documentation
has gotten less verbose and helpful.

llvm-svn: 195189
2013-11-20 04:01:38 +00:00
Chandler Carruth 8c60bc9211 [PM] Fix an iterator problem spotted by the MSVC debug iterators and
AaronBallman. Thanks for the excellent review.

llvm-svn: 194857
2013-11-15 21:56:44 +00:00
Chandler Carruth 1205a6c0c1 [PM] Run clang-format on a few lines that I missed in my first pass,
pulling them under 80-columns. No functionality changed.

llvm-svn: 194856
2013-11-15 21:44:35 +00:00
Chandler Carruth 74015a7084 Introduce an AnalysisManager which is like a pass manager but with a lot
more smarts in it. This is where most of the interesting logic that used
to live in the implicit-scheduling-hackery of the old pass manager will
live.

Like the previous commits, note that this is a very early prototype!
I expect substantial changes before this is ready to use.

The core of the design is the following:

- We have an AnalysisManager which can be used across a series of
  passes over a module.
- The code setting up a pass pipeline registers the analyses available
  with the manager.
- Individual transform passes can check than an analysis manager
  provides the analyses they require in order to fail-fast.
- There is *no* implicit registration or scheduling.
- Analysis passes are different from other passes: they produce an
  analysis result that is cached and made available via the analysis
  manager.
- Cached results are invalidated automatically by the pass managers.
- When a transform pass requests an analysis result, either the analysis
  is run to produce the result or a cached result is provided.

There are a few aspects of this design that I *know* will change in
subsequent commits:
- Currently there is no "preservation" system, that needs to be added.
- All of the analysis management should move up to the analysis library.
- The analysis management needs to support at least SCC passes. Maybe
  loop passes. Living in the analysis library will facilitate this.
- Need support for analyses which are *both* module and function passes.
- Need support for pro-actively running module analyses to have cached
  results within a function pass manager.
- Need a clear design for "immutable" passes.
- Need support for requesting cached results when available and not
  re-running the pass even if that would be necessary.
- Need more thorough testing of all of this infrastructure.

There are other aspects that I view as open questions I'm hoping to
resolve as I iterate a bit on the infrastructure, and especially as
I start writing actual passes against this.
- Should we have separate management layers for function, module, and
  SCC analyses? I think "yes", but I'm not yet ready to switch the code.
  Adding SCC support will likely resolve this definitively.
- How should the 'require' functionality work? Should *that* be the only
  way to request results to ensure that passes always require things?
- How should preservation work?
- Probably some other things I'm forgetting. =]

Look forward to more patches in shorter order now that this is in place.

llvm-svn: 194538
2013-11-13 01:12:08 +00:00
Chandler Carruth 7caea41545 Move the old pass manager infrastructure into a legacy namespace and
give the files a legacy prefix in the right directory. Use forwarding
headers in the old locations to paper over the name change for most
clients during the transitional period.

No functionality changed here! This is just clearing some space to
reduce renaming churn later on with a new system.

Even when the new stuff starts to go in, it is going to be hidden behind
a flag and off-by-default as it is still WIP and under development.

This patch is specifically designed so that very little out-of-tree code
has to change. I'm going to work as hard as I can to keep that the case.
Only direct forward declarations of the PassManager class are impacted
by this change.

llvm-svn: 194324
2013-11-09 12:26:54 +00:00
Andrew Trick b5e1e6cc11 Revert "Encapsulate PassManager debug flags to avoid static init and cxa_exit."
Working on a better solution to this.

This reverts commit 7d4e9934e7ca83094c5cf41346966c8350179ff2.

llvm-svn: 190990
2013-09-19 06:02:43 +00:00
Andrew Trick f33d6df899 Encapsulate PassManager debug flags to avoid static init and cxa_exit.
This puts all the global PassManager debugging flags, like
-print-after-all and -time-passes, behind a managed static. This
eliminates their static initializers and, more importantly, exit-time
destructors.

The only behavioral change I anticipate is that tools need to
initialize the PassManager before parsing the command line in order to
export these options, which makes sense. Tools that already initialize
the standard passes (opt/llc) don't need to do anything new.

llvm-svn: 190974
2013-09-18 23:31:16 +00:00
Andrew Trick dc073addc5 whitespace
llvm-svn: 190973
2013-09-18 23:31:10 +00:00
Craig Topper 31ee5866de Use SmallVectorImpl::iterator/const_iterator instead of SmallVector to avoid specifying the vector size.
llvm-svn: 185540
2013-07-03 15:07:05 +00:00
Dmitri Gribenko 3238fb7595 Add ArrayRef constructor from None, and do the cleanups that this constructor enables
Patch by Robert Wilhelm.

llvm-svn: 181138
2013-05-05 00:40:33 +00:00
Eli Bendersky b35a211f61 Measure time that IR parsing took as part of the -time-passes measurement.
llvm-svn: 178662
2013-04-03 15:33:45 +00:00
Michael Ilseman c33b6ac7c9 Use a DenseMap instead of a std::map for AnalysisID -> Pass* maps. This reduces the pass-manager overhead from FPPassManager::runOnFunction() by about 10%.
llvm-svn: 176072
2013-02-26 01:31:59 +00:00
Craig Topper 821d6af6c2 Remove extra blank line between closing curly brace and 'else'
llvm-svn: 174492
2013-02-06 06:50:38 +00:00
Chandler Carruth 9fb823bbd4 Move all of the header files which are involved in modelling the LLVM IR
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

llvm-svn: 171366
2013-01-02 11:36:10 +00:00
Chandler Carruth ef860a2488 Rename VMCore directory to IR.
Aside from moving the actual files, this patch only updates the build
system and the source file comments under lib/... that are relevant.

I'll be updating other docs and other files in smaller subsequnet
commits.

While I've tried to test this, but it is entirely possible that there
will still be some build system fallout.

Also, note that I've not changed the library name itself: libLLVMCore.a
is still the library name. I'd be interested in others' opinions about
whether we should rename this as well (I think we should, just not sure
what it might break)

llvm-svn: 171359
2013-01-02 09:10:48 +00:00